Ants of the tribe Dacetini are especially diverse in Southeastern North America, with 40 known species, all in the genera Pyramica and Strumigenys. The 30 native Pyramica may represent a remnant Arctotertiary forest ant fauna. The 9 introduced species of Pyramica and Strumigenys come from both Old and New World tropics. Surveys of the southeastern fauna appear incomplete, and there may be additional undescribed species. All species are predatory, capturing small arthropods, especially Collembola, by means of a specialized jaw-snapping mechanism. The notable diversity in mandibular structure among species is unexplained in a functional sense. Arrays of specialized clypeal hairs, usually species-specific, may possibly lure prey. Specialized “spongiform bodies” in the petiolar area may be defensive. Local populations may be threatened by habitat loss, invasive exotic species, and climate change.